I tried a pair of these socks on a recent antelope hunt in Western South Dakota. We had very cold weather for early October. 10 degrees with snow and wind met us as we started our first day of hunting.
I have a 1200 gram Thinsulate boot and my feet stayed warm and dry. The sock wicked away my sweat. I had a boot dryer along and this dried out my boots nicely.
I was impressed with the socks as they kept my feet warm and dry. I can't ask for much more than that out of a sock.